/**
 * Created by haopengjie on 2016/8/25.
 */
(function (doc, win) {
    var docEl = doc.documentElement,
        resizeEvt = 'orientationchange' in window ? 'orientationchange' : 'resize',
        recalc = function ()
        {
            var clientWidth = docEl.clientWidth;
            if (!clientWidth) return;
            if(clientWidth>=640)
            {
                docEl.style.fontSize = '100px';
            }
            else
            {
                docEl.style.fontSize = 100 * (clientWidth / 750) + 'px';
            }
        };
    if (!doc.addEventListener) return;
    win.addEventListener(resizeEvt, recalc, false);
    doc.addEventListener('DOMContentLoaded', recalc, false);
})(document, window);